The present invention relates to hacksaws and, more particularly, to hacksaws with telescoping frames.
Hacksaws are widely employed for cutting metal and the like, and various blades are made from different metal alloys or provided with special cutting coatings for use therein. Moreover, depending upon the workpiece to be cut, hacksaws with different length blades may be used to provide a longer or shorter cutting stroke. Seven and nine inch blades are fairly standard, and some hacksaws are provided with frames which will permit adjustment in the length of their bridge portion to enable use of blades of multiple sizes.
In most instances, the frames use telescoping elements to provide the adjustment and some provide detents, pins, rivets or other means to provide some stability in the adjusted positions. Some hacksaw frames providing such adjustability with good positioning elements are rather expensive to fabricate, and others provide positioning elements which are not particularly effective or which are relatively short lived. As will be appreciated, slippage of the frame in length from its adjusted position can produce undesired compressive of other forces on the blade. Illustrative of such devices are Whelpley U.S. Pat. No. 487,358, Adell et al U.S. Pat. No. 1,473,803, McIntire U.S. Pat. No. 1,565,861 and Spartivento U.S. Pat. No. 1,569,408. In such telescoping constructions, one of the frame elements generally fits within a channel or cylindrical cavity formed in the other, and there is provided some form of locking on the two elements to maintain the frame in an adjusted position.
For several years, Applicants' assignee, The Stanley Works, has marketed a telescoping hacksaw frame utilizing a rear frame member having an inverted channel shaped configuration in which is received a bar-shaped front frame member. A rivet is provided in the channel shaped rear member and it seats in relatively narrow but deep notches formed in the front frame member. A relatively wide slot is provided in the top wall of the rear member adjacent the rivet in order to permit pivoting of the front element relative to the rear frame member in order to effect relative sliding motion Although this structure has been generally satisfactory, it has presented some problems from the standpoint of relative weakness in the area where maximum stress occurs, i.e., about the engagement between the two elements.
It is an object of the present invention to provide a novel telescoping hacksaw frame which may be fabricated economically and which enables stable positioning of the frame elements in their adjusted position.
It is also an object to provide such a frame which may be adjusted simply and quickly.
Another object is to provide such a frame in which the components may be fabricated from sheet metal or like stock by relatively economical and simple techniques.